Structural and electronic properties of thin fluorite-structure NiSi2, CoSi2and FeSi2interfaces and precipitates in Si

✍ Scribed by Wardle, M. G. ;Goss, J. P. ;Briddon, P. R. ;Jones, R.

• Book ID: 105363080
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 193 KB
• Volume: 202
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200460508

✦ Synopsis

Abstract

Interface geometry and electronic properties of fluorite‐structure NiSi~2~, CoSi~2~ and FeSi~2~ layers in {111} oriented silicon are studied using density functional methods. Of the atomically flat geometries studied, NiSi~2~ is found to preferentially form an interface where the transition‐metal atoms are 7‐fold coordinated, whereas CoSi~2~ and γ‐FeSi~2~ both adopt 8‐fold coordinations. Schottky‐barrier heights are detailed for the low energy interface structures of the three disilicides. The localisation of states introduced below the Si valence band and in the band‐gap are detailed for infinite systems, with preliminary results for finite layers simulated by dislocation dipoles also being discussed. Our calculations support the view that gap‐states for silicide precipitates are associated with bounding dislocations rather than the planar interfaces. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)